1. Field
The present invention relates to a fuel cell.
2. Description of the Related Art
A fuel cell, for example, a direct methanol fuel cell (DMFC) of the active type has a structure comprising a single cell having a membrane type electrode unit including a fuel electrode to which an aqueous methanol solution is supplied as a fuel, an air electrode to which an oxidizing gas is supplied, and an electrolyte membrane interposed between these electrodes; and a fuel separator and an oxidizing gas separator disposed at both sides of the membrane type electrode unit.
Such a fuel cell has not been provided with safety measures against an incidental leakage of a fuel.
On the other hand, Jpn. Pat. Appln. KOKAI Publication No. 2004-146179 discloses a fuel cell of a structure having a moisture absorber disposed in a piping system for supplying an oxidizing gas such as air to an air electrode. However, the moisture absorber is disposed in the piping system as a moisture releasing member for preventing an electrolyte membrane from being dried, and it is not intended to prevent leakage of a fuel.
Jpn. Pat. Appln. KOKAI Publication No. 2004-127659 discloses that, when an aqueous methanol solution is supplied as a fuel to a fuel cell, the aqueous methanol solution is stored in a storage material (absorbent) composed of a high molecular compound containing an imidazolium ion in a skeleton, and the aqueous methanol solution is released from the storage material.